CONVERSTION CHART

HARDNESS CONVERSION CHART

Approximate Hardness Conversion Numbers for Nonaustenitic Steels

(Rockwell C to other Hardness Numbers)

Rockwell C Scale, 150-kgf Load, Diamond PenetratorVickers Hardness NumberBrinell Hardness, 3000-kgf Load, 10-mm BallKnoop Hardness, 500-gf Load and OverRockwell A Scale, 60-kgf Load, Diamond Penetrator15N Scale, 15-kgf Load, Diamond Penetrator30N Scale 30-kgf Load, Diamond Penetrator45N Scale, 45-kgf Load, Diamond PenetratorApproximate Tensile Strength, ksi (MPa)
4848445551074.784.566.752.5238 (1640)
4747144249574.183.965.851.4229 (1580)
4645843248073.683.564.850.3221 (1520)
4544642146673.183.064.049.0215 (1480)
4443440945272.582.563.147.8208 (1430)
4342340043872.082.062.246.7201 (1390)
4241239042671.581.561.345.5194 (1340)
4140238141470.980.960.444.3188 (1300)
4039237140270.480.459.543.1182 (1250)
3938236239169.979.958.641.9177 (1220)
3837235338069.479.457.740.8171 (1180)
3736334437068.978.856.839.6166 (1140)
3635433636068.478.355.938.4161 (1110)
3534532735167.977.755.037.2156 (1080)
3433631934267.477.254.236.1152 (1050)
3332731133466.876.653.334.9149 (1030)
3231830132666.376.152.133.7146 (1010)
3131029431865.875.651.332.5141 (970)
3030228631165.375.050.431.3138 (950)
2929427930464.674.549.530.1135 (930)
2828627129764.373.948.628.9131 (900)
2727926429063.873.347.727.8128 (880)
2627225828463.372.846.826.7125 (860)
2526625327862.872.245.925.5123 (850)
2426024727262.471.645.024.3119 (820)
2325424326662.071.044.023.1117 (810)
2224823726161.570.543.222.0115 (790)
2124323125661.069.942.320.7112 (770)
2023822625160.569.441.519.6110 (760)

Approximate Hardness Conversion Numbers for Nonaustenitic Steels

(Rockwell B to other Hardness Numbers)

Rockwell B Scale 100-kgf Load 1/16-in. (1.588-mm) BallVickers Hardness NumberBrinell Hardness, 3000-kgf Load, 10-mm BallKnoop Hardness, 500-gf Load and OverRockwell F Scale, 60-kgf Load, 1/16-in. (1.588-mm) BallRockwell F Scale, 60-kgf Load, 1/16-in. (1.588-mm) Ball15T Scale, 15-kgf Load, 1/16-in. (1.588-mm) Ball30T Scale, 30-kgf Load, 1/16-in. (1.588-mm) Ball45T Scale, 45-kgf Load, 1/16-in. (1.588-mm) BallApproximate Tensile Strength ksi (MPa)
10024024025161.593.183.172.9166 (800)
9923423424660.992.882.571.9114 (785)
9822822824160.292.581.870.9109 (750)
9722222223659.592.181.169.9104 (715)
9621621623158.991.880.468.9102 (705)
9521021022658.391.579.867.9100 (690)
9420520522157.691.279.166.998 (675)
9320020021657.090.878.465.994 (650)
9219519521156.490.577.864.892 (635)
9119019020655.890.277.163.890 (620)
9018518520155.289.976.462.889 (615)
8918018019654.689.575.861.888 (605)
8817617619254.089.275.160.886 (590)
8717217218853.488.974.459.884 (580)
8616916918452.888.673.858.883 (570)
8516516518052.388.273.157.882 (565)
8416216217651.787.972.456.881 (560)
8315915917351.187.671.855.880 (550)
8215615617050.687.371.154.877 (530)
8115315316750.086.970.453.873 (505)
8015015016449.586.669.752.872 (495)
7914714716148.986.369.151.870 (485)
7814414415848.486.068.450.869 (475)
7714114115547.985.667.749.868 (470)
7613913915247.385.367.148.867 (460)
7513713715046.899.685.066.447.866 (455)
7413513514746.399.184.765.746.865 (450)
7313213214545.898.584.365.145.864 (440)
7213013014345.398.084.064.444.863 (435)
7112712714144.897.483.763.743.862 (425)
7012512513944.396.883.463.142.861 (420)
6912312313743.896.283.062.441.860 (415)
6812112113543.395.682.761.740.859 (405)
6711911913342.895.182.461.039.858(400)

SURFACE ROUGHNESS

Ra (micrometers)Ra (microinches) RMSCLA (N)RtNCut-off Length
inchmm
0.02511.110.310.0030.08
0.0522.220.520.010.25
0.144.440.830.010.25
0.288.881.240.010.25
0.41617.6162.050.010.25
0.83232.5324.060.030.8
1.66364.3638.070.030.8
3.2125137.51251380.12.5
6.32502752502590.12.5
12.550055050050100.12.5
25.0100011001000100110.38.0
50.0200022002000200120.38.0

Ra = Roughness Average in micrometers or microinches.
RMS = Root Mean Square in microinches
CLA = Center Line Average in Microinches
Rt = Roughness Ttal in microns
N = New ISO (grade) scale numbers
Порезка = Length required for sample.

INCHES TO MM

inchMetric (mm)inchMetric (mm)
1/46.35376.2
5/167.943 1/879.37
3/89.533 1/482.55
7/1611.113 3/885.72
1/212.73 1/288.9
9/1614.293 5/892.07
5/815.883 3/495.25
11/1617.463 7/898.42
3/419.054101.6
13/1620.644 1/8104.77
7/822.234 1/4107.95
15/1623.814 3/8111.12
125.44 1/2114.3
1 1/828.574 5/8117.47
1 1/431.754 3/4120.65
1 3/834.934 7/8123.82
1 1/238.15127
1 5/841.285 1/8130.17
1 3/444.455 1/4133.52
1 7/847.635 3/8136.8
250.85 1/2139.7
2 1/853.975 5/8142.87
2 1/457.155 3/4146.05
2 3/860.325 7/8149.22
2 1/263.56152.4
2 5/866.676 1/8155.57
2 3/469.856 1/4158.75
2 7/873.026 3/8161.92

FEET TO MM

Feet (ft’)Meter (Mtr)Feet (ft’)Meter (Mtr)
10.3216.4
20.61226.71
30.91237.01
41.22247.32
51.52257.62
61.83267.92
72.13278.23
82.44288.53
92.74298.84
103.05309.14
113.35319.45
123.66329.75
133.963310.06
144.273410.36
154.573510.67
164.883610.97
175.183711.28
185.493811.58
195.793911.89
206.14012.19
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